Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: (B)PSK test results on saturday

To: [email protected]
Subject: LF: (B)PSK test results on saturday
From: [email protected]
Date: Sat, 27 Nov 2004 17:10:48 -0500
Reply-to: [email protected]
Sender: [email protected]
Hello group,

Some "on air"-tests performed saturday evening showed no big difference in the 
performance of PSK08 with amplitude shaping and "slow phase" variation. Thanks to DF6NM's 
grabber (with the zoomed range switched to 136500 Hz temporarily) I could not observe a broader 
signal when switching between the two PSK shaping methods.

Also interesting: Shortly after starting, DL3ZID called me (also in PSK08), and Eberhard was 
perfect copy (as long as no local QRM carriers wiped him out) with 5 mW ERP from over 100 km's 
distance, though the PSK signal was almost invisible on the QRSS3-spectrogram. So the good old 
waterfall display may be not very helpful to detect the presence of such a signal - unless a kind 
of "weak pilot tone" if added to the signal, which would allow to adjust the RX frequency 
manually (by moving the L.O. frequency with a mouseclick into the waterfall, etc). During the QSO 
with DL3ZID, the AFC'ed RX frequency was pulled away several times by "wandering 
carriers" so I finally turned it off (no problem, since DL3ZID's TX frequency was stable 
enough).

Locking the "soft" L.O. to a selectable Loran line may be another option to 
circumvent these problems.. but that's another story.

Regards,
Wolf DL4YHF.

<Prev in Thread] Current Thread [Next in Thread>